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Reference Information • People and Discoveries • Commonly Encountered Radionuclides • Americium-241 • Cesium-137 • Cobalt-60 • Iodine-129 &-131 • Plutonium • Radium • Radon • Strontium-90 • Technetium-99 • Tritium • Thorium • Uranium • Glossary • Acronyms • A-Z Subject Index • Site Map You are here: EPA Home Radiation Protection References Reference Information Radionuclides Radium



# Radium Radium (chemical symbol Ra) is a naturally-occurrin g radioactive metal. Its most common isotopes are rad ium-226, radium 224, and radium-228. Radium is a radionuclid e formed by the decay of uranium and thorium in the environm ent. It occurs at low levels in virtually all rock, soil, w ater, plants, and animals. On this page: The Basics • Who discovered radium? • Where does radium come from? • What are the properties of radium? • What is radium used for? Exposure to Radium • How does radium get into the environment? • How does radium change in the environment? • How do people come in contact with radium? • How does radium get into the body? • What does radium do once it gets into the body? Health Effects of Radium • How can radium affect people's health? • Is there a medical test to determine exposure to r adium? Protecting People from Radium • How do I know if I'm near radium? • What can I do to protect myself and my family from radium? • What is EPA doing about radium?



### The Basics
Who discovered radium?



## Radiation Protection http://www.epa.gov/radiation/radionuclides/radium.h tml Last updated on 3/6/2012



### Page 1 of 6 Radium | Radiation Protection | US EPA

1/ 13/2014 http://www.epa.gov/radiation/radionuclides/radium.htmlRadium was discovered in 1898 by French physicist a nd Nobel laureate Marie Curie in

pitchblende (a uranium and radium-bearing mineral). There is about 1 gram of radium in 7 tons of pitchblende. Elemental radium was isolated by Mme. Curie in 1911.

Where does radium come from? Radium forms when isotopes of uranium or thorium de cay in the environment. Most radium (radium-226) originates from the decay of the plent iful uranium-238. In the natural environment, radium occurs at very l ow levels in virtually all rock, soil, water, plants, and animals. When uranium (or thorium) occu rs in high levels in rock, radium is often also found in high levels.

What are the properties of radium? Radium is a naturally radioactive, silvery-white me tal when freshly cut. It blackens on exposure to air. Purified radium and some radium compounds glow in t he dark (luminesce). The radiation emitted by radium can also cause certain materials, called "phosphors" to emit light. Mixtures of radium salts and appropriate phosphors were wide ly used for clock dials and gauges before the risks of radium exposure were understood. Metallic radium is highly chemically reactive. It forms compounds that are very similar to barium compounds, making separation of the two elem ents difficult. The various isotopes of radium originate from the r adioactive decay of uranium or thorium. Radium-226 is found in the uranium-238 decay series , and radium-228 and -224 are found in the thorium-232 decay series. Radium-226, the most common isotope, is an alpha em itter, with accompanying gamma radiation, and has a half-life of about 1600 years. Radium-228, is principally a beta emitter and has a half-life of 5.76 years. Radium-224, an a lpha emitter, has a half life of 3.66 days. Radium decays to form isotopes of the radioactive g as radon, which is not chemically reactive. Stable lead is the final product of this lengthy radioactive decay series.

What is radium used for? In the early 1900's, when it was newly discovered, no one understood the dangers of radium. People were fascinated with its mysterious properti es, especially the luminescence produced when it is mixed with a phosphor. Industries sprang up to manufacture hundreds of consumer products containing radium. Advertisementsproclaimed its special powers and unique effects in such products such as hair tonic, toothpaste, ointments, and elixirs. Glow in the dark watch and clock faces were immensely popul ar. Most of its original uses have been halted for heal th and safety reasons, but its wide use in luminescent paints continued through World War II, because the soft glow of radium's luminescence made aircraft dials, gauges and other instruments visible to their operators at night. Radium was also an early radiation source fo r cancer treatment. Small seeds were 

### Page 2 of 6 Radium | Radiation Protection | US EPA

1/ 13/2014 http://www.epa.gov/radiation/radionuclides/radium.htmlimplanted in tumors to kill cancerous cells. Safer, more effective radiation sources, such as

cobalt-60 have mostly replaced it. Radium is a radiation source in some industrial rad iography devices, a technology similar to x-ray imaging used in industry to inspect for flawsin metal parts. When radium is mixed with beryllium it becomes a good source of neutrons, use ful in well logging devices and research. Radium also has been added to the tips of lightenin g rods, improving their effectiveness by ionizing the air around it.


### Exposure to Radium How does radium get into the environment? Radium occurs naturally in the environment. As a de cay product of uranium and thorium, it is common in virtually all rock, soil, and water. Usua lly concentrations are very low. However, geologic processes can form concentrations of natur ally radioactive elements, especially uranium and radium. Radium and its salts are solubl e in water. As a result, groundwater in areas where concentrations of radium are high in su rrounding bedrock typically has relatively high radium content.

How does radium change in the environment? All isotopes of radium are radioactive. As they dec ay, they emit radiation and form new radioactive elements, until they reach stable lead. Isotopes of radium decay to form different isotopes of radon. For example, radium-226 decays t o radon-222, and radium-228 goes through several decays to radium-224 before forming radon-220.

How do people come in contact with radium? Since radium is present at low levels in the natura l environment, everyone has some minor exposure to it. However, individuals may be exposed to higher levels of radium if they live in an area where there is an elevated level of radium in the surrounding rock and soil. Private well water in such areas can also be an added sourc e of radium. The concentration of radium in drinking water is ge nerally low, but there are specific geographic regions in the United States where highe r concentrations of radium occur in water due to geologic sources. Limited information is ava ilable about the amounts of radium that are typically present in food and air, but they are very low. People can also be exposed to radium if it is relea sed into the air from the burning of coal or other fuels. Certain occupations can also lead to h igh exposures to radium, such as working in a uranium mine or in a plant that processes ores . Phosphate rocks typically contain relatively high levels of both uranium and radium a nd can be a potential source of exposure in areas where phosphate is mined. In some parts of the country, former radium process ing plants exist that were highly contaminated with radium. However, most of these ha ve been cleaned up and do not pose a serious health threat any longer. 

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1/ 13/2014 http://www.epa.gov/radiation/radionuclides/radium.htmlRadium emits several different kinds of radiation, in particular, alpha and gamma radiation.

Alpha radiation is only a concern if radium is take n into the body through inhalation or ingestion. Gamma radiation, or rays, can expose ind ividual even at a distance. As a result, radium on the ground, for example, can expose indiv iduals externally to gamma rays or be inhaled or ingested with contaminated food or water . The greatest health risk from radium in the environment, however, is actually its decay pro duct radon, which can collect in buildings.

How does radium get into the body? People may swallow radium with food and water, or m ay inhale it as part of dust in the air. Radium can also be produced in the body from "paren t" radionuclides (uranium and thorium) that have been inhaled or swallowed, but this is no t a significant source.

What does radium do once it gets into the body? Most radium that is swallowed (about 80%) promptly leaves the body through the feces. The other 20% enters the bloodstream and accumulates pr eferentially in the bones. Some of this radium is excreted through the feces and urine over a long time. However, a portion will remain in the bones throughout the person's lifetim e.



### Health Effects of Radium How can radium affect people's health? Radium emits several different kinds of radiation, in particular, alpha particles and gamma rays. Alpha particles are generally only harmful if emitted inside the body. However, both internal and external exposure to gamma radiation i s harmful. Gamma rays can penetrate the body, so gamma emitters like radium can result in exposures even when the source is a distance away. Long-term exposure to radium increases the risk of developing several diseases. Inhaled or ingested radium increases the risk of developing su ch diseases as lymphoma, bone cancer, and diseases that affect the formation of blood, su ch as leukemia and aplastic anemia. These effects usually take years to develop. External exp osure to radium's gamma radiation increases the risk of cancer to varying degrees in all tissues and organs. However, the greatest health risk from radium is from exposure to its radioactive decay product radon. It is common in many soils and can c ollect in homes and other buildings.

• Radon This fact sheet describes the basic properties and uses, and the hazards associated with this radionuclide. It also discusses radiation protection related to it. • Radon Home Page This site provides information about the hazards an d management of radon. 

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1/ 13/2014 http://www.epa.gov/radiation/radionuclides/radium.htmlIs there a medical test to determine exposure to ra dium?

There are tests that can determine exposure to radi um or other radioactive substances. For example, a whole body count can measure the total a mount of radioactivity in the body, and urine and feces can be tested for the presence of radionuclides. These tests are not routinely performed in a doctor 's office because it requires special laboratory equipment. There is no test that can det ect external exposure to radium's gamma radiation, unless the doses were very high, and cel lular damage is detectable.


### Protecting People from Radium
How do I know radium if I'm near radium? You need special equipment to detect the presence o f radium. However, you can buy radon detection kits at most hardware stores.

What can I do to protect myself and my family from radium? The most effective way to protect yourself and your family is to test your home for radium's decay product, radon.

• Radon Home Page This site provides information about the hazards an d management of radon.
What is EPA doing about radium? The U.S. Congress passes laws that authorize EPA an d other federal agencies, to protect public health and the environment from radium and o ther radioactive materials. EPA has issued a variety of regulations that limit the rele ase of radium and other radionuclides to the environment. For example, Congress passed the Urani um Mill Tailings Radiation Control Act (UMTRCA). EPA has established standards for cleanin g up and managing leftover uranium ore at inactive ore-processing plants under the authori ty of UMTRCA. The U.S. Department of Energy is responsible for conducting the cleanups, and the U.S. Nuclear Regulatory Commission oversees and manages them.

• UMTRCA This page provides a summary and link to the full s tatute. Complementing these efforts, EPA's Superfund progra m identifies abandoned industrial sites contaminated with radium and other radionuclides an d chemicals. It then assesses the health and environmental risks the sites pose, and assignspriorities for cleaning them up based on those risks. Superfund regulations require sites to be cleaned up to the point that people living on the sites after cleanup would have no mor e than a 1-in-10,000 to a 1-in-1,000,000 increased risk of developing cancer from exposure t o contaminants. 

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1/ 13/2014 http://www.epa.gov/radiation/radionuclides/radium.html• CERCLA This page provides a summary and a link to the comp lete statute. • Superfund This site contains information about individual Sup erfund sites. Other laws passed by Congress address specific envi ronmental media. The Clean Air Act authorizes EPA to establish annual limits, known asNational Emission Standards for Hazardous Air Pollutants, for the maximum amount of radium and other radionuclides that may be released to the air. For radium the "NESHAP" is 10 millirem. The Safe Drinking Water Act authorizes EPA to limit the Maximum ContaminantLevels of radium and other radionuclides in publicly supplied drinking water. For 226 and 228 radium, the MCL is 5 picocuries per liter and for 224 radium it is 15pCi /l. Both the air and water standards limit the increased lifetime cancer risk to about 2 in 10,000

.

• Clean Air Act This page provides a summary and a link to the comp lete act. • Safe Drinking Water Act This page provides a summary and a link to the comp lete act.

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